It is unlawful to kill a non-Muslim to whom a Muslim has given his guarantee of protection (O: whether the non-Muslim is one or more than one, provided the number is limited, and the Muslim’s protecting them does not harm the Muslims, as when they are spies) provided the protecting Muslim has reached puberty, is sane, and does so voluntarily (O: and is not a prisoner of them or a spy).

No, the New York & Washington were not under treaties of protection. Did he violate O9.12?

Whoever enters Islam before being captured may not be killed or his property confiscated, or his young children taken captive.

No, there is no evidence that the victims had embraced Islam. Did he violate O9.6?

It is offensive to conduct a military expedition against hostile non-Muslims without the caliph’s permission (A: though if there is no caliph (def: o25), no permission is required).

No, the Caliphate was dissolved after WW1, he did not need permission. Was it failure to invite and warn the victims? No, the Sheikh performed that duty in 1986,1989 & 2000.